Southern California -- this just in

Unusually cold July in L.A. brings more drizzle, less sizzle

July 6, 2010 | 12:44
pm

The cool air, the low clouds, the dewy breeze on the windshield -- got to love that June gloom! Oh, wait, it's July.

The thick marine layer, cloudy skies and less than scorching weather that is often a hallmark of not only June, but also May ("May gray") is not ready to go away. On Tuesday morning, commuters drove Los Angeles' freeways under a steady drizzle.

"The June gloom that forgot to show up last month is spilling over into July," said Bill Patzert, a climatologist for the Jet Propulsion Laboratory in La Canada-Flintridge. "This is Mother Nature's air conditioner."
Weather scientists say cool ocean air, aided and abetted by a swirling, counterclockwise mass of air around the Catalina Islands, has been keeping Southern California cooler than normal.

Instead of daytime highs approaching the mid-80s, downtown L.A. has been getting temperatures in the mid to high 70s, said Stuart Seto, a weather specialist for the National Weather Service in Oxnard.
Seto said that from June 1 to July 5, the daytime and nighttime temperatures have averaged a relatively cool 69.8 degrees.

That makes that stretch one of the cooler ones for that time of the year in the last 10 years, just slightly warmer than June 1 to July 5 in 2004 (69.4) and 2002 (68.9), Seto said.
The cooler ocean air earlier in the day is moderating the temperatures for the rest of the day, he said. And low-lying clouds have been tempering the sun's heat.

"There's just a very deep marine layer. Sometimes it's so deep, with so much moisture, you'll get drizzle out of it," he said.
Seto and Patzert said a rush of warmer air from Arizona should warm things up by either late this week or the weekend, though it's unclear whether that system will be strong enough to reverse the July gloom.

But by the middle of July, Patzert said, L.A. normally reverts back to its quintessentially hot summer days.

"Enjoy the onshore flow," Patzert said. "The scorchers of August, September and the fall Santa Anas are in our future."